Questions tagged [fossils]

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15
votes
2answers
425 views

What, if any, paleoclimate data can be derived from stromatolite fossils?

Stromatolite fossils have a layered structure vaguely reminiscent of tree rings, which are a well-known source for climate data. Although the formation process of stromatolite layers is less seasonal ...
12
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4answers
7k views

Why are many fossils found in deserts?

Why are deserts famous for fossils? Is it a coincidence? Some examples: Giant Catfish Fossil Found in Egyptian Desert Chile's stunning fossil whale graveyard explained Giant Dinosaur Fossil Found ...
11
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1answer
480 views

What periods of the fossil record are most lacking in specimens?

What parts of the fossil record are most lacking in specimens? That is, if you were to trace the evolution of a modern mammal (humans, for example) from abiogenesis to now, which periods are the most ...
11
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1answer
6k views

How can I tell if a rock is really petrified wood?

I found a rock in the Mojave desert and it resembles a tree branch including what appears to be wood grain. Is there some test or observation that can be done at home to conclusively answer my ...
10
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1answer
171 views

How would a Mars rover identify a microbialite fossil?

I recently read of a company in Canada using robotic technology to study freshwater microbialites. Their claim is that greater understanding of terrestrial microbialites could help in the search for ...
9
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2answers
725 views

How do scientists determine the absolute or 'chronometric' date of fossils?

Absolute dating is the process of determining an approximate computed age of something like a fossil. How does that work?
9
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1answer
408 views

What geological processes can cause local biases in the fossil record?

What are the main geological processes that can cause local biases in the fossil record, e.g. when comparing species diversity or species occurances in different areas from the same time period? I ...
8
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2answers
21k views

How can I learn to spot fossils and fossil-bearing rocks on the Jurassic coast?

Due to a pleasant change in my circumstances, I have been to Lyme Regis several times recently, and it seems as though I'm going to be a regular visitor over the next few years. As a former biologist ...
8
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1answer
648 views

Is the Principle of Fossil Succession accurate?

After wondering on the validity of the principle of Original Horizontality, I'm now focusing on the principle of fossil succession. This principle states that : Fossils of species that did not ...
8
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1answer
368 views

What are Ordovican trace fossils, and what do they look like?

There are some unusual structures in recent images from the Mars Curiosity Rover's MAHLI (Mars Hand Lens Imager) shown in the Space.com article Curiosity Rover Spots Weird Tube-Like Structures on Mars....
7
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2answers
1k views

Life on Earth previous to us

I've seen in several places that there seems to be an extinction cycle on Earth of approximately 27 million years. I've read this here: http://www.dailymail.co.uk/sciencetech/article-1294372/Life-...
7
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1answer
329 views

What is the oldest fossil on Earth?

What is the oldest fossil ever found on Earth? Where and when was it found? What was the oldest fossil with a brain with 2 hemispheres ever found?
7
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0answers
37 views

What geographical features facilitate amber fossilization?

Image source: Wikimedia. There seems to be a few places in the world where amber (fossilized tree resin) can be found in large quantities: Amber can be found in many places around the world ...
6
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1answer
176 views

What are these lines on this stone?

I found this on Lake Ontario in Canada. I was wondering is there is anything special/out of the ordinary about it?
6
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1answer
914 views

How can a non-geologist identify a rock? [closed]

I found a rock on a beach in north-east Evia, Greece. Half is light gray, and half is dark gray. There are white (or very light gray) thin lines that form swirls throughout, crossing the light/dark ...
6
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2answers
83 views

Curious natural patterns on the surface of basalt blocks that make up the sidewalk

During one of my walks through the city streets, I noticed that some basalt blocks that make up the sidewalk have in their surface some very curious natural patterns: The photos above was taken at ...
6
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2answers
247 views

Fossil or Pseudofossil?

I found these rocks in the Oregon Coast Range many years ago and have always wondered whether the interesting image was a pseudofossil or an actual fossil. If it's a pseudofossil, any ideas on how it ...
6
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1answer
1k views

How to identify a predator's coprolite from an herbivore's?

I have a coprolite that is 8" by 5" and weighs 8 lbs. The shape is similar to a lumpy brain, the colors below outer crust are deep red and the crust is pastel green and grey. It has a strong density ...
5
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2answers
764 views

What is Oligo-Miocene radiation?

Some studies about Earth's fosilized plants/animals mention a "Oligo-Miocene radiation". Examples: Our study therefore strengthens previous suggestions that the absence of very large penguins ...
5
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2answers
290 views

ID on a potential flint fossil

I was out in Swinley Forest in Bracknell(United Kingdom) last weekend. The area is a large pine forest but the ground is full of flint and is very sandy. I stumbled across a piece of flint and ...
5
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2answers
92 views

Has there ever been a case where we have found what appears to be a prehistoric fossil but have no way of dating it?

I find that when ever I learn of a new fossil, the age of said fossil is always mentioned. This perplexes me given how intuitively rare it seems to have radioactive material to date a formation. I ...
5
votes
1answer
115 views

Why the $\delta \, ^{18}\text{O}$ in foraminifera shells decrease with temperature even if the oceanic $\delta \, ^{18}\text{O}$ stay constant?

I understand why foram shells contain more $^{18}\text{O}$ when there are ice sheets present, since $^{16}\text{O}$ evaporates more readily and gets trapped in the ice, increasing the relative ...
5
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1answer
459 views

Circular patterns at bottom of rock, is it a fossil?

The image below was taken on a hike. Circular patterns at bottom (it is flatter on this face and round otherwise) appear either man-made or possibly it is a fossil. Any idea what this could be?
5
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1answer
180 views

Geological feature - what is it?

Hello, We were walking in Bundoran in Donegal County, Ireland today and we encountered the geological feature shown in the picture (from above from cliffs and from very close up at beach level). We ...
4
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2answers
458 views

Aligator or Dinosaur Fossil skin type rock

The more I looked at this stone and touched it, the more this thing looked like it was wrapped in some kind of reptile skin. It may just be a random rock. More photos if needed. Does this look like ...
4
votes
1answer
342 views

I have found this fossil tooth, could it be pliosaur ? Or maybe theropod?

Lenght: 10 mm, striated, circular cross-section Site: Brno-Hády (limestone quarry), Moravia, Czech republic, central Europa Age: Jurassic, oxford The site is a good source of fossil shark teeth, ...
4
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1answer
262 views

A sedimentary rock with only minerals

In my text book I came across this multiple-choice question A sedimentary rock consists of only minerals and lacks fossils, it could be classified as: i) a clastic sedimentary rock ii) a chemical ...
4
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2answers
202 views

“Impression and pseudomorphism” in fossils

In a book on invertebrate paleontology I have (Treatise on Invertebrate Palaeontology, A) there is a diagram showing possible fates of a shell after the death of the organism. One of the possible ...
4
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1answer
500 views

Fossil or Beef Limestone?

I found the below sample on Monmouth Beach near Lyme Regis and I am unsure if it is a fossil or simply beef limestone. The beef limestone is from fibrous calcite layers within a shale (known as shales ...
3
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4answers
2k views

How long could a steel artifact last?

Would man made steel artifacts be able to be preserved like fossils for millions of years, or would corrosion make it dissipate? What about metals such as aluminum that dont corrode as easily?
3
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5answers
856 views

Why does mineral oil occur below natural gas?

Why does mineral oil occur below natural gas? It was asked in our science book in the Geology section and I didn't get a clear explanation from the teacher.
3
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1answer
207 views

Fossil from North Norfolk coast, UK

This palm-sized rock is from the beach at Eccles-on-Sea (North Sea coastline). I can see four types of material: A brown, slightly translucent, 6cm tubular fossil(?) that I can mark with a steel ...
3
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1answer
1k views

Why don't animals rot when trapped in amber? [closed]

I just saw an image of a gecko stuck in amber 58 million years ago. Why don't animals rot when they are trapped in amber? I've seen dry insects whose chitin shells persist for a long time away from ...
3
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1answer
131 views

What type of mammal does this fossil tooth belong to?

The fossil tooth was found western South Dakota in the early 1980s. I can't be sure on the location. It might have been collected from Belle Reservoir, near Belle Fourche, Butte County, South Dakota, ...
3
votes
2answers
191 views

How long ago was the first limestone formed?

It is readily apparent from the fossil record that the first limestone was laid down hundreds of millions of years ago, but how long ago was the very first limestone formed? It could be approximately ...
3
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2answers
27 views

Is there any significance of lacustrine gastropoda fossils regarding paleoenviroment interpretation?

How to interpret lots of gastropoda fossils seen in lacustrine marls? Do they indicate any paleoenvironment conditions? Depth, temperature, chemistry, ph?
3
votes
1answer
540 views

How old are Pecten fossils in general?

Many years ago, I found a piece of rock on a lakeside in Switzerland (see picture below). I think that it could be a "fossil" from some Pecten species (do you agree?). My question is: how old such ...
3
votes
1answer
131 views

Donation Options for Fossil and Mineral Collection

The father of a friend of mine passed away recently. He left behind an extensive collection of fossils and minerals. They include a saber tooth tiger skull, mastodon tooth, shark teeth, tons of ...
3
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0answers
49 views

Continuous production of amber by trees in one location

In which well known amber location did trees produce amber for the longest continuous period of time, roughly how long was it, and was it long enough to see signs of evolution at work in any of the ...
3
votes
2answers
122 views

Is there a massive drop in quality of Cretaceous vs. Triassic dinosaur fossils?

One thing that still blows my mind about dinosaurs is the massive timeline. Relevant to this question are the time periods: Triassic Period (252.17 to 201.3 million years ago) Cretaceous Period (145 ...
2
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1answer
309 views

How quickly can coral fossilize?

On a trip to Honduras a few years ago I visited one of the islands off its north coast with a friend and went to a section of it mostly with nothing but residences which looked far less visited by ...
2
votes
1answer
155 views

How Good is The Evidence For Snowball Earth?

Some geologists say there were times between 770 million years BP and 630 million years BP when ice ages were so profound that the Arctic and Antarctic ice caps met at the equator. This is called the ...
2
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1answer
51 views

Can hippopotamus fossils be found all along the Nile?

The image below shows their historical range (red) and current range (green) of hippopotamuses: Image source: Six Surprising Facts About Hippos, 2014 Hence my question... Question: Can hippopotamus ...
2
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2answers
78 views

Fossil in Chert pebble picked up on a Kent beach

Please identify the fossil in the picture below. size of pebble is around 40mm diameter and the pebble had been broken to reveal the internal structure.
2
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0answers
20 views

Looking for videos/GIFs of petrification/permineralization

Do you know of any good animations, videos, or GIFs of petrification/permineralization? For some students verbal and written explanations don’t work, they don't always visualize well. So it’d be ...
2
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1answer
42 views

What is the time period of these chalk/clay layers?

These limestone-clay rocks are very common in the Alps, they come from weather changes. How many years does it take to make one of the rock bands? 7 years, equivalent to an el-nino type event? 1000 ...
2
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0answers
366 views

Are fossils in slate 3 dimensional or does the slate split open at the weakest point where the flat imprint of the fossil is found?

In this picture you see a fossil of an Ammonite. When you break a slate with a hammer it will fall apart so sometimes you can find a fossil. But is this fossil only there in the slate just at the ...
2
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1answer
177 views

What kind of tooth is this?

Please help me identify this tooth and the era its from. I found it in Panama City Beach Florida. Its cold and hard when i bite it. It looks very old. Possibly a shark tooth?
1
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2answers
135 views

What is this strange fossil I found?

I found this weird fossil rock and I am wondering if anybody could help identify what could have made the imprint in it or what kind of rock it is?
1
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1answer
116 views

Who can it belong to? fossil tooth

**Tooth was found in Baltic Sea, near Lithuanian coast, **